How Deep Is The Sewer Line From The Surface?

Deep Sewer Lines

Digging up a trench with sewer pipes is easy when you know the dimension of cut. Sewage pipes often connect with street sewer lines and municipal treatment facilities. So, plumbers must maintain a range between 12 to 36 inches when laying underground pipes. Do you know the main points to observe when replacing your home’s sewer lines?

Ensure Freeze Protection for Pipes

Different environmental factors determine the depth of a building’s main sewer and drain line. Usually, sewer lines that are deeper than 20 inches survive freezing temperatures during winter months. Homeowners hire contractors to dig up and reposition shallow sewer pipes before this period. According to New York’s plumbing code, the trench’s width should be between 1 to 3 feet. Additionally, plumbing contractors must maintain between a width of 6 feet between successive trenches for drain pipes.

Consider the Weight of Earth-Moving Machines

The depth of sewer lines must allow for convenient parking of vehicles on their paths. When cars roll over the paths with sewer and drain lines, the compact soil helps to withstand the weight and pressure. Usually, modern building structures on shallow water tables use maximum depth of 24-inch trenches for sewer lines. The construction with PVC, clay, or cast-iron sewer pipelines in places with high seasonal high water tables can be in trenches that are 36 inches deep. 

Burying Sewer Pipes along Garden and Lawn Spaces

It’s proper for the entry port of main sewer lines to be under any type of landscaping. Here on the field, plumbers don’t have to dig too deep because of the soft soil. Also, gardens or homeowners must grow plants with short root systems to prevent obtrusions on plastic sewer pipes. By using flowers with shallow root systems, the threat on pipes will reduce, and a depth of 15 inches is suitable. This is extremely important as tree roots in drains have been one of the major blockage causes that have been reported over the years.

What to Ensure When Constructing Sewer Systems?


Follow Building Codes and Regulations

Digging a trench down a densely compacted soil is an initial preparation for pipe laying process. The pipes require some good soil compaction, concrete, and steel reinforcement. While ensuring compliance with plumbing codes, building contractors implement sewer system designs with rough-ins. The installation of sewage and wastewater pipe to septic tanks will need to pass plumbing inspections at the end of the project. 

Maintain a Suitable Slope Range

The depth of a modern building’s main drain exit point to bigger pipes on the street should maintain a standard slope range. Generally, the variation between 1/8-1/4″ per foot allows wastewater and sewage to drain with enough gravity. With this design, the wastewater and sewage can flow into their septic tank entry pipes. Most functional sewer piping systems have considerable depth of the pipes and slope range too. One last thing to note the shape is designed to minimise the chances of getting a blocked drain, making it very durable.

Provide Schematic Diagrams

Every site construction for plumbing systems needs schematic diagrams to ensure proper implementation. The sketch should outline important fixtures, exit, entry, and connection points to guide plumbing engineers and technicians. Usually, drain piping depths for sewer lines, slope range, and spacing between trenches carry their measurements. By representing the sketch map elements with different colour codes, it’s easy for plumbers to ensure regular preventive maintenance. Also, ground slopes should be labelled with special colours.

Protect Drain Lines with Pavements

Your building’s foundation wall structure should maintain a minimum distance from septic tanks. When sewer lines are well-installed, it improves the longevity of other plumbing fixtures. Also, structures like sewer tanks, risers, and access ports, and pipes should be protected from encroachments by pets and children. Homeowners can construct pavements along the lawn to guide drain pipes from trespass.